linux-dev/arch/arm64/kvm, branch linus/master

KVM: arm64: Remove redundant hyp_assert_lock_held() assertions

2022-06-09T12:24:02Z

host_stage2_try() asserts that the KVM host lock is held, so there's no need to duplicate the assertion in its wrappers. Signed-off-by: Will Deacon Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20220609121223.2551-6-will@kernel.org

KVM: arm64: Ignore 'kvm-arm.mode=protected' when using VHE

2022-06-09T12:24:02Z

Ignore 'kvm-arm.mode=protected' when using VHE so that kvm_get_mode() only returns KVM_MODE_PROTECTED on systems where the feature is available. Cc: David Brazdil Acked-by: Mark Rutland Signed-off-by: Will Deacon Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20220609121223.2551-4-will@kernel.org

KVM: arm64: Handle all ID registers trapped for a protected VM

2022-06-09T12:24:02Z

A protected VM accessing ID_AA64ISAR2_EL1 gets punished with an UNDEF, while it really should only get a zero back if the register is not handled by the hypervisor emulation (as mandated by the architecture). Introduce all the missing ID registers (including the unallocated ones), and have them to return 0. Reported-by: Will Deacon Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20220609121223.2551-3-will@kernel.org

KVM: arm64: Return error from kvm_arch_init_vm() on allocation failure

2022-06-09T12:24:02Z

If we fail to allocate the 'supported_cpus' cpumask in kvm_arch_init_vm() then be sure to return -ENOMEM instead of success (0) on the failure path. Reviewed-by: Alexandru Elisei Signed-off-by: Will Deacon Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20220609121223.2551-2-will@kernel.org

KVM: arm64: Warn if accessing timer pending state outside of vcpu context

2022-06-08T09:16:23Z

A recurrent bug in the KVM/arm64 code base consists in trying to access the timer pending state outside of the vcpu context, which makes zero sense (the pending state only exists when the vcpu is loaded). In order to avoid more embarassing crashes and catch the offenders red-handed, add a warning to kvm_arch_timer_get_input_level() and return the state as non-pending. This avoids taking the system down, and still helps tracking down silly bugs. Reviewed-by: Eric Auger Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20220607131427.1164881-4-maz@kernel.org

KVM: arm64: Replace vgic_v3_uaccess_read_pending with vgic_uaccess_read_pending

2022-06-08T09:16:15Z

Now that GICv2 has a proper userspace accessor for the pending state, switch GICv3 over to it, dropping the local version, moving over the specific behaviours that CGIv3 requires (such as the distinction between pending latch and line level which were never enforced with GICv2). We also gain extra locking that isn't really necessary for userspace, but that's a small price to pay for getting rid of superfluous code. Signed-off-by: Marc Zyngier Reviewed-by: Eric Auger Link: https://lore.kernel.org/r/20220607131427.1164881-3-maz@kernel.org

KVM: arm64: Don't read a HW interrupt pending state in user context

2022-06-07T15:28:19Z

Since 5bfa685e62e9 ("KVM: arm64: vgic: Read HW interrupt pending state from the HW"), we're able to source the pending bit for an interrupt that is stored either on the physical distributor or on a device. However, this state is only available when the vcpu is loaded, and is not intended to be accessed from userspace. Unfortunately, the GICv2 emulation doesn't provide specific userspace accessors, and we fallback with the ones that are intended for the guest, with fatal consequences. Add a new vgic_uaccess_read_pending() accessor for userspace to use, build on top of the existing vgic_mmio_read_pending(). Reported-by: Eric Auger Reviewed-by: Eric Auger Tested-by: Eric Auger Signed-off-by: Marc Zyngier Fixes: 5bfa685e62e9 ("KVM: arm64: vgic: Read HW interrupt pending state from the HW") Link: https://lore.kernel.org/r/20220607131427.1164881-2-maz@kernel.org Cc: stable@vger.kernel.org

KVM: arm64: Fix inconsistent indenting

2022-06-07T14:27:05Z

Fix the following smatch warnings: arch/arm64/kvm/vmid.c:62 flush_context() warn: inconsistent indenting Reported-by: kernel test robot Signed-off-by: sunliming Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20220602024805.511457-1-sunliming@kylinos.cn

KVM: arm64: Always start with clearing SME flag on load

2022-06-07T13:31:30Z

On each vcpu load, we set the KVM_ARM64_HOST_SME_ENABLED flag if SME is enabled for EL0 on the host. This is used to restore the correct state on vpcu put. However, it appears that nothing ever clears this flag. Once set, it will stick until the vcpu is destroyed, which has the potential to spuriously enable SME for userspace. As it turns out, this is due to the SME code being more or less copied from SVE, and inheriting the same shortcomings. We never saw the issue because nothing uses SME, and the amount of testing is probably still pretty low. Fixes: 861262ab8627 ("KVM: arm64: Handle SME host state when running guests") Signed-off-by: Marc Zyngier Reviwed-by: Mark Brown Link: https://lore.kernel.org/r/20220528113829.1043361-3-maz@kernel.org

KVM: arm64: Always start with clearing SVE flag on load

2022-06-07T13:19:23Z

On each vcpu load, we set the KVM_ARM64_HOST_SVE_ENABLED flag if SVE is enabled for EL0 on the host. This is used to restore the correct state on vpcu put. However, it appears that nothing ever clears this flag. Once set, it will stick until the vcpu is destroyed, which has the potential to spuriously enable SVE for userspace. We probably never saw the issue because no VMM uses SVE, but that's still pretty bad. Unconditionally clearing the flag on vcpu load addresses the issue. Fixes: 8383741ab2e7 ("KVM: arm64: Get rid of host SVE tracking/saving") Signed-off-by: Marc Zyngier Cc: stable@vger.kernel.org Reviewed-by: Mark Brown Link: https://lore.kernel.org/r/20220528113829.1043361-2-maz@kernel.org